A method for analyzing fatigue life of steering knuckle

Abstract

The invention discloses a method for analyzing the fatigue life of a steering knuckle, comprising the following steps: 1) obtaining the fatigue load of the steering knuckle; 2) carrying out uniaxial tensile material test on the use material; 3) if the fatigue load is under the static load condition, the elastic-plastic finite element analysis method is adopted to solve the problem; or, if it is the actual pavement load spectrum, the elastic-plastic finite element analysis is carried out on the points exceeding the yield strength by elastic finite element method and linear superposition method,and the modified stress-strain results are obtained. 4) analyzing the biaxiality of the obtained stress response in time domain to determine the load state of the steering knuckle; 5) calculating thedamage accumulation and life of steering knuckle. The present invention solves the problem of time-consuming finite element solution under the input of actual pavement load spectrum, at the same time, the stress and strain of the material entering the plastic phase are considered, so that the result is more accurate, and fatigue analysis is carried out by combining the static load condition or the single channel static load condition, and more references are provided in the design phase.

Description

technical field [0001] The invention relates to a method for analyzing the fatigue life of automobile parts, in particular to a method for analyzing the fatigue life of an automobile steering knuckle. Background technique [0002] Automobile steering knuckle is an important safety component in automobile suspension. Its function is mainly to connect the wheel and the body and carry the sprung mass. At the same time, the steering knuckle of the steering bridge is also responsible for driving the wheels to turn. The vertical force, lateral force, longitudinal force and braking torque of the wheel are directly transmitted to the steering knuckle. If the steering knuckle breaks and breaks during use, serious accidents are likely to occur, so there are greater requirements for the structural performance of the steering knuckle. During the actual use of the car, the loads on the parts of the car are all alternating loads, and their amplitudes vary randomly. Under the action of th...

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Problems solved by technology

[0003] For the fatigue performance verification of parts, there are usually laboratory bench tests, proving ground road tests and actual road fatigue durability tests. Development cycle and cost, if the fatigue simulation analysis can be carried out in the design stage, and the structure can be improved in time, the test cost can be reduced to a certain extent and the product development cycle can be shortened

[0004] However, at present, when conducting part-level tests on steering knuckles, there are few simulation verifications in the design stage. When performing fatigue simulations that simulate the actual road load spectrum, most current methods only consider the elastic phase of the material and ignore In order to avoid the plastic strain generated under some relatively extreme working conditions, the prior art also lacks a more effective fatigue life analysis method when there is no actual road load spectrum of the steering knuckle

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